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From: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
To: dev@dpdk.org, honnappa.nagarahalli@arm.com, alialnu@mellanox.com,
	orgerlitz@mellanox.com, wenzhuo.lu@intel.com,
	beilei.xing@intel.com, bernard.iremonger@intel.com,
	ferruh.yigit@intel.com
Cc: hemant.agrawal@nxp.com, jerinj@marvell.com,
	viacheslavo@mellanox.com, thomas@monjalon.net,
	ruifeng.wang@arm.com, phil.yang@arm.com, nd@arm.com,
	zhihong.wang@intel.com, stable@dpdk.org
Subject: [dpdk-dev] [PATCH v3 1/3] app/testpmd: clock gettime call in throughput calculation
Date: Mon,  6 Jul 2020 18:32:29 -0500	[thread overview]
Message-ID: <20200706233231.25881-1-honnappa.nagarahalli@arm.com> (raw)
In-Reply-To: <20200617144307.9961-1-honnappa.nagarahalli@arm.com>

The throughput calculation requires a counter that measures
passing of time. However, the kernel saves and restores the PMU
state when a thread is unscheduled and scheduled. This ensures
that the PMU cycles are not counted towards a thread that is
not scheduled. Hence, when RTE_ARM_EAL_RDTSC_USE_PMU is enabled,
the PMU cycles do not represent the passing of time.
This results in incorrect calculation of throughput numbers.
Use clock_gettime system call to calculate the time passed since
last call.

Bugzilla ID: 450
Fixes: 0e106980301d ("app/testpmd: show throughput in port stats")
Cc: zhihong.wang@intel.com
Cc: stable@dpdk.org

Signed-off-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Reviewed-by: Phil Yang <phil.yang@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
Reviewed-by: Ferruh Yigit <ferruh.yigit@intel.com>
Tested-by: Phil Yang <phil.yang@arm.com>
Tested-by: Ali Alnubani <alialnu@mellanox.com>
---
v3:
1) Dropped 'noisy vnf' patch, will add with future Dharmik's patch
2) Dropped flow gen patch, send out a separate one if there is
   consensus on the mailing list
3) Changed the logic to display burst stats to make it easier
   to understand (Ferruh)

v2: Updated commit log in 1/5 (Jerin)

 app/test-pmd/config.c | 44 +++++++++++++++++++++++++++++--------------
 1 file changed, 30 insertions(+), 14 deletions(-)

diff --git a/app/test-pmd/config.c b/app/test-pmd/config.c
index 016bcb09c..91fbf99f8 100644
--- a/app/test-pmd/config.c
+++ b/app/test-pmd/config.c
@@ -54,6 +54,14 @@
 
 #define ETHDEV_FWVERS_LEN 32
 
+#ifdef CLOCK_MONOTONIC_RAW /* Defined in glibc bits/time.h */
+#define CLOCK_TYPE_ID CLOCK_MONOTONIC_RAW
+#else
+#define CLOCK_TYPE_ID CLOCK_MONOTONIC
+#endif
+
+#define NS_PER_SEC 1E9
+
 static char *flowtype_to_str(uint16_t flow_type);
 
 static const struct {
@@ -136,9 +144,10 @@ nic_stats_display(portid_t port_id)
 	static uint64_t prev_pkts_tx[RTE_MAX_ETHPORTS];
 	static uint64_t prev_bytes_rx[RTE_MAX_ETHPORTS];
 	static uint64_t prev_bytes_tx[RTE_MAX_ETHPORTS];
-	static uint64_t prev_cycles[RTE_MAX_ETHPORTS];
+	static uint64_t prev_ns[RTE_MAX_ETHPORTS];
+	struct timespec cur_time;
 	uint64_t diff_pkts_rx, diff_pkts_tx, diff_bytes_rx, diff_bytes_tx,
-								diff_cycles;
+								diff_ns;
 	uint64_t mpps_rx, mpps_tx, mbps_rx, mbps_tx;
 	struct rte_eth_stats stats;
 	struct rte_port *port = &ports[port_id];
@@ -195,10 +204,17 @@ nic_stats_display(portid_t port_id)
 		}
 	}
 
-	diff_cycles = prev_cycles[port_id];
-	prev_cycles[port_id] = rte_rdtsc();
-	if (diff_cycles > 0)
-		diff_cycles = prev_cycles[port_id] - diff_cycles;
+	diff_ns = 0;
+	if (clock_gettime(CLOCK_TYPE_ID, &cur_time) == 0) {
+		uint64_t ns;
+
+		ns = cur_time.tv_sec * NS_PER_SEC;
+		ns += cur_time.tv_nsec;
+
+		if (prev_ns[port_id] != 0)
+			diff_ns = ns - prev_ns[port_id];
+		prev_ns[port_id] = ns;
+	}
 
 	diff_pkts_rx = (stats.ipackets > prev_pkts_rx[port_id]) ?
 		(stats.ipackets - prev_pkts_rx[port_id]) : 0;
@@ -206,10 +222,10 @@ nic_stats_display(portid_t port_id)
 		(stats.opackets - prev_pkts_tx[port_id]) : 0;
 	prev_pkts_rx[port_id] = stats.ipackets;
 	prev_pkts_tx[port_id] = stats.opackets;
-	mpps_rx = diff_cycles > 0 ?
-		diff_pkts_rx * rte_get_tsc_hz() / diff_cycles : 0;
-	mpps_tx = diff_cycles > 0 ?
-		diff_pkts_tx * rte_get_tsc_hz() / diff_cycles : 0;
+	mpps_rx = diff_ns > 0 ?
+		(double)diff_pkts_rx / diff_ns * NS_PER_SEC : 0;
+	mpps_tx = diff_ns > 0 ?
+		(double)diff_pkts_tx / diff_ns * NS_PER_SEC : 0;
 
 	diff_bytes_rx = (stats.ibytes > prev_bytes_rx[port_id]) ?
 		(stats.ibytes - prev_bytes_rx[port_id]) : 0;
@@ -217,10 +233,10 @@ nic_stats_display(portid_t port_id)
 		(stats.obytes - prev_bytes_tx[port_id]) : 0;
 	prev_bytes_rx[port_id] = stats.ibytes;
 	prev_bytes_tx[port_id] = stats.obytes;
-	mbps_rx = diff_cycles > 0 ?
-		diff_bytes_rx * rte_get_tsc_hz() / diff_cycles : 0;
-	mbps_tx = diff_cycles > 0 ?
-		diff_bytes_tx * rte_get_tsc_hz() / diff_cycles : 0;
+	mbps_rx = diff_ns > 0 ?
+		(double)diff_bytes_rx / diff_ns * NS_PER_SEC : 0;
+	mbps_tx = diff_ns > 0 ?
+		(double)diff_bytes_tx / diff_ns * NS_PER_SEC : 0;
 
 	printf("\n  Throughput (since last show)\n");
 	printf("  Rx-pps: %12"PRIu64"          Rx-bps: %12"PRIu64"\n  Tx-pps: %12"
-- 
2.17.1


  parent reply	other threads:[~2020-07-06 23:32 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-17 14:43 [dpdk-dev] [PATCH 1/5] " Honnappa Nagarahalli
2020-06-17 14:43 ` [dpdk-dev] [PATCH 2/5] app/testpmd: enable burst stats for flowgen mode rx path Honnappa Nagarahalli
2020-06-18 14:57   ` Phil Yang
2020-06-17 14:43 ` [dpdk-dev] [PATCH 3/5] app/testpmd: enable burst stats for noisy vnf mode Honnappa Nagarahalli
2020-06-18  7:16   ` Jens Freimann
2020-06-17 14:43 ` [dpdk-dev] [PATCH 4/5] app/testpmd: fix burst percentage calculation Honnappa Nagarahalli
2020-06-18 15:01   ` Phil Yang
2020-06-23 13:33   ` Ali Alnubani
2020-06-17 14:43 ` [dpdk-dev] [PATCH 5/5] app/testpmd: enable empty polls in burst stats Honnappa Nagarahalli
2020-06-18 15:05   ` Phil Yang
2020-06-23 13:34   ` Ali Alnubani
2020-06-17 15:16 ` [dpdk-dev] [PATCH 1/5] app/testpmd: clock gettime call in throughput calculation Jerin Jacob
2020-06-18  4:03   ` Honnappa Nagarahalli
2020-06-18 10:16     ` Jerin Jacob
2020-06-18 15:08 ` Phil Yang
2020-06-23 13:33 ` Ali Alnubani
2020-06-26 22:09 ` [dpdk-dev] [PATCH v2 " Honnappa Nagarahalli
2020-06-26 22:09   ` [dpdk-dev] [PATCH v2 2/5] app/testpmd: enable burst stats for flowgen mode rx path Honnappa Nagarahalli
2020-07-06 16:02     ` Ferruh Yigit
2020-07-06 17:06       ` Honnappa Nagarahalli
2020-07-06 17:17         ` Ferruh Yigit
2020-07-06 18:46           ` Honnappa Nagarahalli
2020-06-26 22:09   ` [dpdk-dev] [PATCH v2 3/5] app/testpmd: enable burst stats for noisy vnf mode Honnappa Nagarahalli
2020-07-06 16:08     ` Ferruh Yigit
2020-07-06 16:59       ` Honnappa Nagarahalli
2020-07-06 17:11         ` Ferruh Yigit
2020-07-06 17:41           ` Honnappa Nagarahalli
2020-06-26 22:09   ` [dpdk-dev] [PATCH v2 4/5] app/testpmd: fix burst percentage calculation Honnappa Nagarahalli
2020-07-06 16:10     ` Ferruh Yigit
2020-06-26 22:09   ` [dpdk-dev] [PATCH v2 5/5] app/testpmd: enable empty polls in burst stats Honnappa Nagarahalli
2020-07-06 17:05     ` Ferruh Yigit
2020-07-06 19:11       ` Honnappa Nagarahalli
2020-07-07  9:32         ` Ferruh Yigit
2020-07-06 15:36   ` [dpdk-dev] [PATCH v2 1/5] app/testpmd: clock gettime call in throughput calculation Ferruh Yigit
2020-07-06 16:53     ` Honnappa Nagarahalli
2020-07-06 17:19       ` Ferruh Yigit
2020-07-06 23:32 ` Honnappa Nagarahalli [this message]
2020-07-06 23:32   ` [dpdk-dev] [PATCH v3 2/3] app/testpmd: fix burst percentage calculation Honnappa Nagarahalli
2020-07-06 23:32   ` [dpdk-dev] [PATCH v3 3/3] app/testpmd: enable empty polls in burst stats Honnappa Nagarahalli
2020-07-07 17:47   ` [dpdk-dev] [PATCH v3 1/3] app/testpmd: clock gettime call in throughput calculation Ferruh Yigit

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